Citations

A weekly look at recent science and technology research conducted at Princeton

Sugar high

Amphetamine is an upper. Sugar can make you hyper. No coincidence, says psychology researchers Nicole Avena GS and rat-loving professor Bart Hoebel. When animals are sensitized to a particular drug, they often become more active when given another drug of the same class. This is called cross-sensitization and has been previously found for amphetamine with cocaine and cocaine with alcohol, the researchers wrote. Avena and Hoebel looked for cross-sensitization of amphetamine and sugar in rats, and they found it. They concluded that amphetamine and sugar probably affect the same systems in the brain, and they hypothesized that, like amphetamine, repeatedly consuming sugar could lead to a sugar dependency.

Pharmacology Biochemistry and Behavior, "Amphetamine-sensitized rats show sugar-induced hyperactivity (cross-sensitization) and sugar hyperphagia." February 2003.

Blocking pores

In the body, antibodies combat antigens by attaching to them. In the lab, scientists and technicians use antibodies to detect the presence of other agents, such as hepatitis, by checking whether the antibodies have become bound to something else. Omar Saleh GS and physics professor Lydia Sohn have developed a new technique for detecting the binding, which could replace the time-consuming and costly methods of using fluorescence, radioactivity or enzyme activity, they wrote in an article published last month. Their all-electronic technique is to measure the change in current over pores. When a large particle passes through a pore, it displaces the fluid in the pore causing the current through the pore to decrease. When an antibody attaches to a large molecule, it cuts off more current. If antigens are then introduced to bind with the antibodies, a different amount of current may be cut off. Thus by measuring the change in current through a pore, the presence of antigens can be determined. The researchers found their method to be faster and more sensitive than current techniques.

Proceedings of the National Academy of Sciences, "Direct detection of antibody-antigen binding using an on-chip artificial pore." Feb. 4, 2003. JOSHUA TAUBERER